Conessine isolated from Holarrhena floribunda

Abstract

The title compound, C24H40N2, has been isolated from Holarrhena floribunda G. Don. (Apocynaceae). The compound has a pentacyclic steroidal nucleus; the ring junctions share the same stereochemistry reported for this class of compounds. Of the three six-membered rings, rings A and C adopt a chair-like and ring B forms a half-chair-like conformation. The cyclopentane ring D shows a half-chair conformation and the methylpyrrolidine ring E adopts an envelope conformation. The dimethylamino substituent in ring A is equatorially oriented.